need a simple foam shader.

Hey !, I work on a project that needs foam after a boat. The current implementation is with a particlesystem, and dont look very well imo. Do anyone have some ideas of a easy solution (i have very limited time). I tought of a shader , maybe a shader ?, but how do i write sucha shader easiest way ?, ... is there anyway to get the particlesystem nicer, any trix? well ty for any fast advices